Leetcode-136-a number that appears only once

subject

Ideas

1. requirement ： Linear time complexity . And it doesn't use extra space to achieve .
2. Oh, this question uses XOR , I seem to have done this question during the interview … Completely forgotten

Code

    public int singleNumber(int[] nums) {
    
        // That is to say, only traverse once   Find the number   The hash table does not meet the requirements of spatial complexity 
        int a=0;
        for(int i=0;i<nums.length;i++){
    
            a = a ^ nums[i];
        }
        return a;
    }